1. Field of the Invention
The invention relates to a lithography system for processing a target, such as a wafer, and a method for operating a lithography system for processing a target, such as a wafer.
2. Description of the Related Art
Systems for processing a target are known in the art, usually comprising a final projection system for projecting a pattern on the target surface and a system for determining the position of a wafer with respect to the final projection system. In general, these systems may use position marks on the wafer. Between a first and a second session of projecting a pattern, it may be required to remove the wafer from the lithography system. In that case, it may be required that the position of the pattern of the second session is matched with the position of the pattern of the first session and that the position of the wafer with respect to the final projection system (or the patterning beam) may have to be determined twice, at the beginning of each session. However, it may be difficult to determine the position of the wafer with respect to the final projection system with a high reproducibility.